A Love Like War
by cacodaemonic
Summary: Aishi Kyohei has never been one for the spotlight, for daring schemes and reckless deeds, has never been as clever and strong-willed as his twin sister, Ayano. But then they find themselves competing against each other, for Senpai's heart, the safety of the school, and Ayano's very sanity... All's fair in love and war... (mxm. rating might change)
1. Phase 00 - Not in the Stars

**A/N:** **Just to clarify a few things:**

 **This story will take place over the course of at least ten weeks, with a rival each week. That is not to say that all the rivals will take a week to eliminate, however.**

 **There may be other rivals that appear in the story, though I haven't quite decided on that yet.**

 **The Yakuza _will_ play a part in this story - how significant, I have also not yet decided.**

 **The fact that many things in the Yandere Simulator universe are still a mystery means that I will be, as writers do, making things up. Besides, the appearance of Kyohei already makes it absolutely clear that this is most definitely not canon, though I'll try to be as accurate as possible.**

 **I'm not entirely familiar with Japanese schooling systems and habits of speech. If any of you are, feel free to correct me when I make mistakes.  
**

 **Finally (and this is a decision that many of you may not like), I've changed Senpai's name from Yamada Taro to Yamada Seishiro. Why? Because Yamada Taro is quite literally (as I'm sure you're all familiar) the Japanese equivalent of John Doe. And I really can't take a character named like that seriously. In any case, _Seishiro_ looks similar enough to _Senpai_ to me, so I much prefer this. Especially since I can't write _Taro_ without thinking of a root vegetable.**

* * *

The soft pink petals of the cherry blossom trees overhead dappled the paths to the school, drifting in the air and spinning lazily down to the ground. It was a beautiful sight, especially outlined against the pristine, posh high school, with the constant thrum of the students greeting each other on the second day back at school, the amicable, friendly atmosphere that hung in the air.

Despite the picturesque scene, Aishi Kyohei was in no way appreciating anything about the situation. His chin was tilted down unconfidently, flicking glances upwards every few seconds from behind his long bangs that were brushed over the left side of his face, covering his discoloured blind eye. He trailed a few steps behind his minutes-older twin sister, awkwardly ducking his head away when the eyes of his schoolmates skipped easily past Ayano but lingered for half a second longer on him.

There really was only himself to blame for that, though. Neither Kyohei nor Ayano had ever been successful at forcing themselves to genuinely like interactions with others, but Ayano was clever enough to pass herself off as a quiet but otherwise completely normal girl. Kyohei's crippling shyness and active avoidance of all social situations had achieved the unfortunate effect of drawing the attention of his confused schoolmates onto him, as they speculated about whatever dark secret he might be hiding.

"I'm in class two-one," Ayano informed Kyohei suddenly, turning to glance back at him almost disinterestedly. "See you at lunch."

She left before Kyohei even had time to respond, leaving him standing alone in the middle of the hallway. He glanced around wildly in a panic, trying to find his classroom – 2-2 – stumbling a little in his haste not to be caught alone in the hallway.

He skidded a little on the slick floors, letting out an involuntary cry of surprise as he went sprawling in the hallway, landing hard on his hands and knees and sending his books skittering over the ground in all directions. He pulled himself painfully back up to a sitting position, letting the back of his head hit the wall, looking slightly despairingly at his books in the hall.

"Hey, are you all right?"

Kyohei's eyes widened, his head snapping upwards to see who it was. The smooth, kind voice came from an upperclassman much taller than he was – though with Kyohei's almost embarrassing height, that wasn't much of an accomplishment – with handsome features, a sharp jawline and concerned hazel eyes. His slightly messy black hair fell into his face, framing his warm smile that was bordering slightly on bemusement when Kyohei failed to answer him.

"Y – yes," Kyohei stammered finally, quickly brushing his hair frantically over his face to make sure his disfigurement was covered up. "I'm fine. Thanks."

Kyohei scrambled to pick up his books, stuffing them hastily into his bag, avoiding the upperclassman's eyes. He knew that he was blushing furiously, in part due to the embarrassing situation, but mostly because of the fact that a very, very attractive student was being so kind to him. He glanced around wildly for his chemistry textbook, his heart sinking when he didn't see it in his bag.

"Hey, no worries. This is yours, right?" The upperclassman held the textbook out towards Kyohei, smiling faintly. Kyohei took it, stuttering more _thank-you_ 's. He blushed even harder when he saw that the upperclassman was holding his hand out, offering it to Kyohei. He took it, allowing him to pull Kyohei to his feet.

"I – I should be getting to class," Kyohei mumbled at the ground. "Thanks for, um…"

"No problem," the other boy said easily. "My names is Yamada, by the way. Yamada Seishiro. Third year."

"Aishi Kyohei," he replied, unable to meet his upperclassman's eyes. "I'm in second year. It was…nice meeting you, Senpai."

Yamada nodded. "Likewise, Aishi. I'll see you around, shall I?"

Kyohei watched as Yamada walked away, unable to tear his eyes away. Yamada Seishiro…had Kyohei seen him around school before? He must have…but how could he have forgotten, disregarded someone like that?

Kyohei let out a small squeak of surprise when the bell sounded, dashing through the hallways and skidding into his classroom seconds late.

"I'm sorry, Risa-sensei!" He gasped, collapsing in his seat. His teacher glanced up at him, shaking her head, but didn't mark him down on the attendance, so he allowed himself to relax with a sigh of relief.

"What kept you?" A boy with slicked back purple-dyed hair asked, twisting in his seat to look Kyohei in his one good eye. "You got to school early enough. I saw you come in with your sister."

"Tell you later, Isami," Kyohei whispered, glancing up at the teacher, who was starting to teach the lesson, hoping that she wouldn't notice their little exchange. He was out of luck, however.

"Aishi, Nakayama! Shall we refrain from disrupting my class?"

Isami called out a cheerful, slightly abashed apology while Kyohei sunk down lower in his chair, his face burning with embarrassment. It felt like every single one of his classmates' eyes were on him, staring at him, judging him, mocking him.

Isami was, perhaps, his only friend. He was something of a social butterfly, and their conversations in the hallways were always interspersed with his responses to their classmates' cheerful greetings. They'd been friends since they were children (something that Kyohei's father had seemed oddly relieved about), and despite Kyohei's fears, Isami had continued to be his friend even after they'd started at Akademi High.

At one point, Kyohei had had other friends, too, who had seemed just as quiet and non-confrontational as he was. Something had changed about them last year, though…they had become withdrawn and nervous, bleak and hopeless. And then, all of a sudden, the five of them had become bold, brash, reckless…they had dyed their hair, they had pierced their skin, carried weapons…

Two of them strode into his class, very late, at that moment. Neither of them paid much heed to Risa-sensei, as a matter of fact, the one with a fearsome scar slashed over his nose only scoffed while his companion sneered, settling into seats at the back of the class and glaring at anyone who so happened to have the misfortune of glancing their way. Kyohei caught the scarred boy's eye, immediately paling when Dairoku rolled his eyes at him and stuck his feet up on his desk. He turned around immediately, and though he didn't see Hayanari's reaction, he heard his mocking laugh.

It was a relief to be able to leave class at lunch, to escape from what he was sure was Dairoku and Hayanari's stares boring into the back of his head, the curious looks his classmates cast at him, and Risa-sensei's disappointment when he mumbled incoherently whenever a question was directed at him.

"Haven't seen them all summer," Isami commented, watching as Dairoku and Hayanari met up with three other boys with identical dyed-blond hair and scowls. "Have you talked to them at all?"

Kyohei shook his head. "Not since April." He followed Isami to their usual spot on the rooftop, trailing half a step behind him.

"Huh, well, you were always pretty good friends with them. Guess they're not really…well, the same, now. Hey, so, why were you late to class? I would've expected you to want to make a good impression on Risa-Sensei, especially on the first day of school."

Isami said all of this incredibly quickly, so that Kyohei was left blinking in bemusement as he tried to keep up.

"Oh, um, I got a little lost," he admitted. "And then I tripped and dropped all my books."

Isami winced in sympathy, glancing at the books in Kyohei's arms. "You really should use your locker, Kyo-kun. It'd save you a lot of work, not having to carry all those around."

"I can never get it to open." Kyohei sighed. "Well, teachers never like me, anyway, so it's not that big of a deal. And my parents are overseas, so it doesn't matter if they call home."

"Yeah, and Yan-chan is hardly going to care," Isami agreed, with a grin that was almost a grimace. "How was your summer, then?"

"Quiet. My parents left about a week ago, so it's just been me and Ayano."

It looked like Isami barely repressed a shudder. He'd been friendly enough to Kyohei's elder twin at first, until Kyohei had lost the sight in his eye. Since then, he'd been polite but wary towards Ayano – and Ayano, for her part, never really seemed to care. Then again, she didn't care about anything, much.

"Wait, this isn't the roof," Kyohei said, realizing very belatedly that they were headed to the front of the school.

"Ah, yeah, since it's so nice out, I thought we could eat by the fountain."

"Oh. Okay, I guess."

It was a nice day out. The sweet, gentle smell of the cherry blossoms pervaded the sunlit scene, the rippling water of the fountain glittering and burbling happily. Isami sat down on a stone bench in front of it and Kyohei scrambled to follow suit. In his haste, though, he tripped over himself and overbalanced, nearly ending up in the lap of another student on the neighbouring bench.

"Oh, sorry, sorry!" Kyohei stammered, straightening himself up and flushing deeply as he stumbled backwards. He gasped, recognizing hazel eyes warm with amusement and messy black hair. "Oh, Senpai, I'm so sorry –"

"It's nothing," Yamada said, the corners of his mouth twitching upwards in a small smile. "Watch where you're going, though, all right? We keep meeting like this, and I wouldn't want you to hurt yourself."

Kyohei nodded frantically, his cheeks feeling very hot. Yamada's eyes were soft, shining with gentle humour, and made Kyohei's stomach flutter and his heart race.

 _Oh_ , he thought helplessly. _Oh, of course._

He'd known that he liked boys for about a year, now. His mother knew, but didn't seem to particularly care, as did Ayano. His father had seemed a little concerned, but ultimately resigned. Outside of his family, only Isami knew.

Isami, who grinned knowingly at him as Kyohei made his way over to him, sitting down beside him with a flaming face and trembling fingers.

"Yamada Seishiro," said Isami.

"Shut up," Kyohei said, burying his face in his hands.

"He's nice, I hear. Really friendly and helpful. I don't think he's really in any clubs, but he's a good student and fairly popular."

"Isami, don't," Kyohei all but begged. Isami sighed in mock-disappointment, but returned to his bento until something seemed to catch his eye.

"There's your sister," Isami observed. "Ah, she looks…different."

Kyohei looked up from his bento. It was, indeed, Ayano, but her features were no longer smooth in neutral disinterest. Instead, her face looked almost flushed, her eyes glassy and gleaming with a peculiarly feverish light. She spotted Kyohei and she seemed to be jerked out of her daze in time to gesture for him to come with her.

"Oh. That's new," Kyohei said blankly. "I – I should see what she wants, I guess?"

Isami murmured his agreement. Kyohei stumbled off after Ayano, who waited for a heartbeat before leading him back into the school.

"A – Ayano?" Kyohei asked hesitantly, as he half-jogged to keep up with her swift strides. "Yan-chan? What's going on?"

Ayano said nothing, simply leading him into an empty classroom. For a moment, all she did was look at Kyohei as he fidgeted nervously, waiting for her to speak.

"I met him," she said finally, her voice trembling with what Kyohei could only describe as excitement. "The one mother told me about. Kyohei, I met him."

"Met…who?"

" _Him_ ," Ayano insisted. "The one, the upperclassman, Senpai. The one that makes me… _feel_ things."

Kyohei's stomach lurched at the ominous admission, and his eye widened involuntarily in a mixture of shock and fear. Of _course_ …

Their mother loved them both in her own way, he was certain – she adored them, but Ayano had always seemed to be her favourite. Kyohei remembered the hushed conversations between his parents when they had been children, and Ayano had hardly spoken to anyone but himself, when his life seemed to be a blur of the white doctors' rooms that Ayano had almost always seemed to be confined to. And then there had been that day, when their mother had taken Ayano aside and assured her that they were one and the same, that she would meet a man who would take her and let her feel, while Kyohei listened in uncomprehendingly. And that had been the day when Ayano had retreated even further into herself, never speaking to even Kyohei for days that stretched into weeks that stretched into months…until she had started to pretend.

He supposed he should be happy – and he was, to know that Ayano might finally be even the slightest bit normal.

"Who is he?" He asked, curious.

The name that fell from Ayano's lips made him freeze, a sinking horror settling into his stomach.

"Yamada Seishiro."


	2. Phase 01 - Bits of Reality

"I'll see you Monday, then?" Isami said, halting at the front doors of the school. Kyohei nodded. "Don't let Yan-chan get to you too much, with your parents gone," Isami said, and though his voice was teasing, there was a hard edge beneath it that was uncharacteristic of his usually carefree attitude.

"I'll be fine, Isami," Kyohei assured him, smiling faintly. "Ayano and I don't do much together, anyway, and I've survived the last week, haven't I? Besides, she's my sister. You act like she could murder me at any second."

Instead of laughing, as Kyohei hoped he might, Isami only jerked his head at Kyohei's left eye, his mouth hardening.

"That was years ago," Kyohei tried to convince him. "It happened when we were eight, 'Sami. Besides, it was an accident."

"Whatever you say."

Kyohei waved as Isami walked off in the opposite direction to the bus stop. He stumbled as a few people jostled him on their way out, clutching his bookbag closer to his chest.

"Watch where you're going!" A girl snapped. She was much taller than Kyohei was, bold and striking with bright orange twin-tails that streamed behind her as she tossed her head, her eyes bright with annoyance as she stalked off.

"Sorry!" Kyohei called, something he seemed to be saying a lot recently. _Even if you were the one that walked into me._

"Are you ready to leave?"

Kyohei nearly started at the sound of Ayano's quiet voice behind him. He'd been with her all his life, but he'd never quite gotten used to how subtly she could come up behind him. Perhaps more eerie was how her voice had changed, now that there was no one in their immediate proximity to hear her. Even around their parents, she kept up the façade of quiet but contented thoughtfulness. Around Kyohei alone, however, perhaps deciding it was too exhausting to pretend when he was always around, she dropped the pretense. She was always flat and entirely inflectionless, something that was reflected in her cool grey eyes that were identical to Kyohei's own. Though she had asked a question, there was no real concern behind it, or any real interest to hear the answer.

"Y – yeah," Kyohei said, stumbling over his words. "Let's go."

The bike ride home was quiet, as it always was. Even if there had been an opportunity to talk between street-crossings, Ayano had never been one for small talk. It gave Kyohei time to lose himself in his thoughts, which wasn't always an entirely enjoyable experience.

His thoughts were wrought with unease. In the past week, he'd learned quite a bit. Yamada Seishiro, from what Isami had told him, was popular and well-known around the school. There were more than a few girls at Akademi High who giggled when he passed by, who fixed their gazes on him wherever he went. And he could understand why – he was brooding and contemplative, but at the same time, friendly and amicable to anyone who approached him. He was tall, with handsome features and slightly messy hair that sometimes fell into his bright hazel eyes. Kyohei didn't have a chance, but, well, there was nothing wrong with admiration from afar. It wasn't as if he would have been brave enough to approach him, even if he had had a chance at all. Besides, he was fairly certain that Yamada's closest friend would have something to say about anyone trying to make a move on him, from what little he'd seen of the two of them together.

Ayano, though, was a different story, and that was what made Kyohei cringe inward with dread.

Ayano didn't want things. She ate and drank because she had to, she talked to classmates and teachers because she had to, she pretended to care, because she had to. Ayano had never wanted anything in her life, never, never…except for one thing.

She wanted to _feel_.

And if Yamada Seishiro was the one that made her feel, then Kyohei didn't know what lengths she would go to in order to make him hers.

It felt like only a few seconds later that they arrived at their home – a pretty white house in a nice neighbourhood, with their father's silver car in the driveway and the little red flowers in the flowerbeds waving cheerfully in the wind, stark against the neatly trimmed lawn. Kyohei followed Ayano as they wheeled their bikes into the garage and entered an empty, silent house.

Uncharacteristically, Ayano didn't immediately drift off to her room. Kyohei rocked back on his heels, biting at his lip and wondering what she was thinking, stood in the middle of their living room.

"I – I have a bit of homework," Kyohei said, to break the silence.

"Najimi Osana," Ayano said suddenly.

Kyohei blinked in surprise. Ayano met his eyes steadily before clarifying…sort of. "She has orange twin tails. She's in my class."

"What about her?" Kyohei asked.

Ayano's grey eyes, previously blank and neutral, became hard and cold. When she spoke again, it was with a chilling emotion that Kyohei had never heard before in her voice, feigned or otherwise. A dark rage that bled into her voice and turned her familiar, plain features into ominous, dark shadows.

"She's trying to take Senpai away from me."

Kyohei's eyes widened, his mouth going suddenly very dry. "Najimi Osana? She's just his friend. Apparently they've been neighbours since they were kids –"

"I know," Ayano said, cutting him off – and of course she did, Kyohei thought in despair, he'd noticed her watching him from afar nearly every single day, noticed that she'd been coming home late nearly every day. "She wants him to be hers. She's planning on confessing to him behind the cherry tree next Friday."

"How…how do you know this?"

"I just do. That's not important, what's important is that she needs to be eliminated."

Kyohei sat down hard on the couch, looking up at Ayano's usually impassive features. Her mouth was twisted strangely, her eyes steely and glinting coldly. There was a sick sensation churning in his stomach, at her features, her tone, her words...

 _Eliminated._ Not...not _persuaded_ , not even _threatened_. Eliminated...

"Why are you telling me this?"

"Because I might need your help. I haven't decided yet. It's essential that Senpai doesn't see me, especially me eliminating her."

"My help." Kyohei swallowed dryly. "My help with what?"

"She feels too entitled to Senpai," Ayano said, her voice dropping lower and crueler in pitch, so that a shiver ran down Kyohei's back. "I'm going to get rid of her and teach her a lesson at the same time. She needs to be taken off of her pedestal, so I'm going to turn the school against her. Not only will Senpai not want her, nobody will, not even her closest friends. She has secrets, she has to – _everyone_ has secrets. I'm going to find it, and I'm going to spread it. If I'm lucky, she won't ever even show her face around Senpai ever again, because she'll be gone from school for good."

Kyohei was almost appalled. While bullying and gossip was a common thing at an elite, snobbish private school such as Akademi High, the fact that Ayano sounded so utterly matter-of-fact made him deeply uneasy.

"You can't do that," he said, his voice shaking slightly. If Ayano noticed, she didn't comment, though her eyes did narrow in suspicion.

"Why not."

It was hardly a question at all – it was dismissive, as if she didn't care much for his answer at all.

"You – she –" how could Kyohei explain _right_ and _wrong_ to someone who didn't care what others thought of her actions, who felt no remorse for things that she had done? "I –"

Ayano seemed to be waiting, now mildly interested to hear whatever fumbling answer had Kyohei so worked up. His heart was hammering in his chest, his mouth suddenly dry and his palms slick with sweat. He usually avoided Ayano, at least when she wasn't pretending. It was sick, perhaps, but he couldn't deny the fact that his sister made him deeply uneasy - though he supposed, he was justified in feeling that way. The thing was, though, he rarely spoke to her one-on-one, and he had never, never tried to oppose her before.

This was different. This was so altogether different. He had never seen her before, like this, never so insistent and cold and ominous.

"She's his best friend," he settled for saying instead, hoping, praying desperately, that it would work. "If you hurt her, it would hurt him." He saw her eyebrows draw together, an indication that she was thinking, and proceeded with renewed hope. "Remember that time that Isami was too sick to go to school? It wasn't my fault, and I couldn't do anything about it, but I was upset, right? It would be like that."

Ayano's lips turned down into a frown, of puzzlement, and of immediate distaste. "I would not like it if Senpai was hurt. But he needs to know that he doesn't need her."

"But, but he's not the one that likes Najimi, right, it's the other way around?" Ayano nodded slowly. "Then just, maybe you could convince her that someone else would be better for her, instead of Yamada-senpai?"

The words tasted strange in his mouth. There was a certain degree of unreality to all this – this was hardly a conversation he would ever have expected to be having. But between distracting Najimi Osana from her currently unrequited love and driving her out of the school, well, Kyohei knew which one he preferred.

"Fine," Ayano said, and Kyohei let out a breath he hadn't known he'd been holding in relief. "There's a boy that likes her, I think, in your class. I'll do something with that. Only to keep Senpai…happy."

But then she frowned, fixing Kyohei with a steely gaze, and Kyohei's heart thudded painfully in his chest.

"But if it's too bothersome, I won't keep it up. No matter what, she has to go. And I don't care who I have to go through to achieve that."

She turned to leave for her room, and Kyohei melted back against the couch cushions, taking in a deep, shuddering breath as quietly as he could manage.

Ayano turned around, suddenly, fixing Kyohei with a level stare that made him jerk upright with anxious fear.

"No one will stand between him and me. Not even you."


End file.
